N-propionyl and N-acetyl derivatives (NPr- and NAcCAP) of 4-S-cysteaminylphenol, that is, sulfur-amine analogue of tyrosine, were synthesized as possible melanoma-targeted drugs (Figure 1) and found to possess selective cytotoxic effects on in vivo and in vitro melanomas through the oxidative stress that derives from production of cytotoxic free radicals by interacting with tyrosinase within melanogenesis cascade [6–10]. The gene discussed is TYR; the disease is melanoma.